How difficult is it to add new activities to an existing project scheduling model? Answer this question by assuming that there are two other activities, labeled P and Q. Activity P moves selected employees to temporary offices while installation occurs, and activity Q moves them back after installation is finished. Activity P has immediate predecessors D and E, immediate successor H, and duration three days. Activity Q has immediate predecessor L, immediate successor O, and duration three days. Find the new project completion time. Does the critical path change because of the new activity?